Do you need an MSO for your ABA practice in Illinois?

Section 150: the ownership cliff

Illinois is the most demanding ownership state in this guide, on par with New York. The Behavior Analyst Licensing Act contains an explicit ownership mandate: beginning 24 months after the Department commenced issuing licenses, no business organization may provide, attempt to provide, or offer to provide behavior analysis services unless every member, partner, shareholder, director, officer, and holder of any other equity interest holds a valid Illinois behavior analyst license (225 ILCS 6/150). This is corporate-practice language written directly into the ABA statute, and it is unusually broad: it reaches not just shareholders but every equity holder, director, and officer.

ABA is a licensed profession in Illinois

The Behavior Analyst Licensing Act was signed into law in 2022 and is administered by the Illinois Department of Financial and Professional Regulation (225 ILCS 6/), which licenses behavior analysts and assistant behavior analysts and began issuing licenses through its online system in January 2025. The general licensure deadline for practitioners not otherwise exempt was March 23, 2025 (225 ILCS 6/20), with the Department deferring enforcement of unlicensed practice to April 21, 2025. So both the individual practitioners and, under Section 150, the owners of the business face licensure requirements.

How Section 150 fits Illinois corporate-practice law

Illinois already strictly enforces a corporate-practice-of-medicine doctrine for physicians, grounded in the Medical Practice Act of 1987 (225 ILCS 60/) and confirmed by the Illinois Supreme Court in Berlin v. Sarah Bush Lincoln Health Center (1997), which barred unlicensed corporations from employing physicians to practice medicine. Section 150 takes that same principle and writes it directly into the behavior-analysis statute, extending an explicit, licensee-only ownership rule to ABA businesses. In other words, Illinois did not leave the question to doctrine: it legislated the answer for ABA.

Who is allowed to own the clinical entity

Under Section 150, the answer is narrow: only licensed Illinois behavior analysts. Every member, partner, shareholder, director, officer, and holder of any other equity interest in a business that provides ABA services must hold a valid Illinois behavior analyst license (225 ILCS 6/150). There is no minority allowance for non-licensees and no carve-out for passive investors. A non-licensee, including a private equity sponsor, a non-clinical co-founder, or a management company, cannot hold equity in the ABA business itself. That is what makes the management-company structure not just advisable but necessary for any outside capital.

What a management services organization actually is

An MSO is a separate company that provides the non-clinical side of a practice to a clinical entity it does not own. The clinical entity employs the licensed clinicians and holds the license. The MSO employs everyone else and runs the business. A management services agreement ties them together, and the clinical entity pays the MSO a fee. In Illinois, the clinical entity must be owned entirely by licensed behavior analysts, and the MSO is where any non-licensee capital lives. Crucially, the MSO must not itself hold equity in the ABA business, because Section 150 reaches every equity holder.

Why the MSO is the only route for outside capital here

Because Section 150 requires every owner and equity holder of the ABA business to be a licensed Illinois behavior analyst, a non-licensee cannot take any equity in the practice. If a non-licensee founder, operating partner, or private equity sponsor wants an economic stake, the compliant path is to own a management company that contracts with the licensee-owned clinical entity. The licensed behavior analysts hold the ABA business outright, and the enterprise value accumulates in the MSO. For groups currently structured with non-licensee owners, the runway to the January 15, 2027 deadline is the window to restructure into this model or divest. See the practice expansion and sale page for the transaction view.

The Attorney General transaction-notice requirement

Illinois layers a second, separate requirement on top of ownership. Effective January 1, 2024, an amendment to the Illinois Antitrust Act requires health care facilities and provider organizations that are party to a covered transaction to give the Illinois Attorney General at least 30 days' notice before closing (740 ILCS 10/7.2a, added by Public Act 103-0526). The provider-organization trigger generally reaches organizations representing 20 or more providers, and out-of-state parties are covered when they generate $10 million or more in annual revenue from Illinois residents. A smaller ABA practice may fall below these thresholds, but a larger platform or a transaction with a covered facility can trigger the filing, so the notice requirement should be screened for in any Illinois ABA transaction.

How Illinois would evaluate your arrangement

In Illinois the questions are unusually concrete because the rule is statutory. These are the factors that decide whether a structure complies.

Fee-splitting and how to pay an MSO

As a corporate-practice state, Illinois treats arrangements that share professional fees with non-licensees with suspicion, so fixed and cost-plus management fees set to fair market value are the safest because they trace to documented services. A percentage-of-revenue fee is riskier and should, if used at all, reflect the fair value of real services rather than function as a way for a non-licensee to share in the practice's professional income. For Illinois Medicaid clients, the federal anti-kickback statute applies on top (42 U.S.C. § 1320a-7b(b)).

Keeping clinical control on the right side of the line

The structure holds only while the MSO stays on the business side, holds no equity in the ABA business, and the licensed behavior analysts keep genuine ownership and authority over clinical decisions, supervision, and professional judgment. In Illinois the ownership line is statutory and dated, so an arrangement that leaves a non-licensee with equity or effective control of the ABA business is not a gray area; it is non-compliant once the deadline passes. Write the documents so ownership and clinical control sit entirely with the licensed behavior analysts.

How this connects to the rest of your compliance stack

Ownership is one layer. Three others interact with it directly, and getting the MSO right does not resolve them:

• Payor and Medicaid disclosure. Your real ownership stack, including any MSO, is disclosed at enrollment and revalidation regardless of how it looks on paper (42 C.F.R. Part 455). See Medicaid and insurance mandates.
• Facility licensure. A change in the ownership or service model can affect facility and records obligations. See facility licensure and HIPAA.
• Entity structure. Restructuring into a 100% licensee-owned clinical entity plus an MSO is its own analysis. See entity structures for ABA practices.

Setting it up in Illinois: the sequence

1. License the practitioners and owners. Behavior analysts licensed through IDFPR, and, critically under Section 150, every owner of the ABA business as well (225 ILCS 6/150).
2. Make the clinical entity 100% licensee-owned. By January 15, 2027, every member, shareholder, director, officer, and equity holder must be a licensed Illinois behavior analyst.
3. Move non-licensee capital to an MSO. A standard LLC or corporation that contracts with the clinical entity and holds no equity in it.
4. Restructure or divest before the deadline. If the current ownership includes non-licensees, plan the transition with counsel well ahead of January 15, 2027.
5. Screen any transaction for the AG notice. Check the covered-transaction thresholds under 740 ILCS 10/7.2a before closing.
6. Confirm with Illinois healthcare counsel. Section 150, its repeal bills, and the transaction-notice law should be reviewed together and kept current.

Illinois MSO variables at a glance

Frequently asked questions